Long-term results of conventional varus half-wedge proximal femoral osteotomy for the treatment of osteonecrosis of the femoral head

Factors related to collapse progression in Japanese Investigation Committee classification type B osteonecrosis of the femoral head

PURPOSE

This study aimed to identify factors related to collapse progression in Japanese Investigation Committee classification type B osteonecrosis of the femoral head (ONFH) and to identify patients who would benefit from surgical treatment.

METHODS

This study included 41 patients (56 hips) with type B ONFH with a minimum follow-up of three years. Based on a ≥ 3 mm collapse progression in ONFH, we categorised patients into two groups: collapse progression and no collapse progression. Sagittal and coronal computed tomography images were used to measure the necrotic region relative to the intact femoral head diameter. The ratios of the necrotic regions of transverse and vertical diameter in coronal and sagittal images are defined as mediolateral transverse and mediolateral vertical, anteroposterior transverse and anteroposterior vertical, respectively. Demographic data and these imaging findings were compared between the two groups. We established a cut-off value for predicting collapse progression through receiver operating characteristic analysis and determined survival rates.

RESULTS

Type B ONFH had a 17.8% collapse progression rate. The mediolateral transverse, mediolateral vertical, anteroposterior transverse, and anteroposterior vertical were significantly higher in the collapse progression group (P < 0.01). Mediolateral transverse was an independent risk factor of collapse progression (hazard ratio, 1.27; 95% confidence interval, 1.03-1.57; P = 0.03), with an optimal cut-off of 45.6%. The 5-year survival rates with collapse progression as the endpoints were 57.0 and 94.9% in the mediolateral transverse of ≥ 45.6 and < 45.6%, respectively.

CONCLUSION

A mediolateral transverse of ≥ 45.6% predicts collapse progression in patients with type B ONFH.

Operative Management of Avascular Necrosis of the Femoral Head in Skeletally Immature Patients: A Systematic Review

Purpose: Osteonecrosis of the femoral head (ONFH) is common in skeletally immature patients. The management of ONFH is controversial, with limited evidence and unpredictable results. This study systematically reviewed the current operative modalities and clinical outcomes of surgical management for ONFH in skeletally immature patients. Methods: The present study was conducted according to the PRISMA 2020 guidelines. PubMed, Google Scholar, Embase, and Web of Science databases were accessed in October 2021. All the published clinical studies reporting data concerning the surgical management of ONFH in skeletally immature patients were included. Results: This review included 122 patients (127 hips). 38.2% (46 of 122) were female. The mean age of the patients was 14.2 ± 2.3 years. The mean duration of the follow-up was 55.3 ± 19.6 months. The Harris Hip Score improved from 68.8 ± 11.9 at baseline to 90.5 ± 6.5 at last follow-up (p < 0.0001). Femoral head collapse and secondary hip degeneration were the most common complications. Conclusion: Several surgical techniques are available and effective for the management of ONFH in skeletally immature patients. This study evidenced high heterogeneity of the surgical procedures and eligibility criteria. Further high-quality investigations are required to establish proper indications and surgical modalities.

Osteotomies for avascular necrosis of the femoral head

BACKGROUND

In osteonecrosis of the femoral head (ONFH), blood supply is insufficient for the metabolic requirements of the bone. The initial management is conservative, and, in case of failure, surgery is indicated. Osteotomies aim to change the spatial position of the necrotic portion of the femoral head. This systematic review evaluates the effectiveness and safety of osteotomies for ONFH.

SOURCE OF DATA

The systematic review, organized, conducted and reported following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines, was performed on PubMed and Google Scholar. We analysed outcomes in term of Harris Hip Score, leg shortening, secondary collapse and blood loss. We also verified the percentage of patients who required total hip replacement (THR) after osteotomy for ONFH.

AREAS OF AGREEMENT

A total of 16 articles were selected, including 775 patients and 852 osteotomies [curved varus osteotomy in 369 (43.3%) patients; transtrochanteric rotational osteotomy in 435 (51.05%) patients; half wedge osteotomy in 48 (5.6%) patients]. There was an overall THR conversion rate of 31.5% (268 hips on 852 osteotomies).

AREAS OF CONTROVERSY

There were no prospective randomized trials, and the outcome measures employed were often heterogeneous.

GROWING POINTS

Approximately one-third of the osteotomies performed in cases of ONFH are converted to THR over a period of ~7 years. In older patients, primary THR should be considered, especially as the conversion to THR after osteotomy is technically demanding.

AREAS TIMELY FOR DEVELOPING RESEARCH

Randomized clinical studies should be conducted in order to define the parameters of the patient that can direct towards the most suitable osteotomic technique.

Japanese Orthopaedic Association 2019 Guidelines for osteonecrosis of the femoral head

PURPOSE

The Clinical Practice Guidelines for Osteonecrosis of the Femoral Head (ONFH) 2019 Edition, written by the working group for ONFH guidelines of the Japanese Investigation Committee (JIC) for ONFH under the auspices of the Japanese Ministry of Health, Labour, and Welfare and endorsed by the Japanese Orthopaedic Association, were published in Japanese in October 2019. The objective of this guideline is to provide a support tool for decision-making between doctors and patients.

METHODS

Procedures for developing this guideline were based on the Medical Information Network Distribution Service Handbook for Clinical Practice Guideline Development 2014, which proposed an appropriate method for preparing clinical guidelines in Japan.

RESULTS

This clinical practice guideline consists of 7 chapters: epidemiology; pathology; diagnosis; conservative therapy; surgical treatment: bone transplantation/cell therapy; surgical treatment: osteotomy; and surgical treatment: hip replacement. Twelve background questions and 13 clinical questions were determined to define the basic features of the disease and to be addressed when deciding treatment in daily practice, respectively.

CONCLUSIONS

The clinical practice guidelines for the ONFH 2019 edition will be useful for physicians, investigators, and medical staff in clinical practice, as well as for patients, during the decision-making process when defining how to treat ONFH.

Comparison of surgical dislocation and impacting bone graft and surgical dislocation and rotational osteotomy for the treatment of ARCO III femoral head necrosis

Hip preserving procedures are still a challenge in late-stage osteonecrosis of femoral head (ONFH) patients. We aimed to compare the clinical outcomes of surgical dislocation and impaction bone graft and surgical dislocation and rotational osteotomy for treatment of ONFH in Association Research Circulation Osseous (ARCO) stage III patients.We retrospectively reviewed 30 ARCO stage III patients (33 hips) who had surgical dislocation and impaction bone graft or surgical dislocation and rotational osteotomy in our center from June 2012 to December 2017. Baseline characteristics, clinical evaluation using Harris score and radiologic evaluation up to 12 months after surgery were recorded and compared.Fifteen patients (17 hips) were in the surgical dislocation and impaction bone graft group and 15 patients (16 hips) were in the surgical dislocation and rotational osteotomy group. No significant differences in age, gender, etiology, ARCO stage, duration of illness, operation time, and length of hospitalization were observed between the 2 groups. Compared to preoperation Harris score, the Harris score of 6 months postoperation and 12 months postoperation significantly improved. At 12 months postoperation, the excellent and good rate was 76.5% in the impaction bone graft group and 87.5% in the rotational osteotomy group. No significant difference in Harris scores was detected in the 2 groups.Surgical dislocation and impaction bone graft and surgical dislocation and rotational osteotomy had satisfactory 1-year efficacy for ARCO III ONFH patients. Surgical dislocation and rotational osteotomy had better short-term efficacy than surgical dislocation and impaction bone graft.

Guidelines for clinical diagnosis and treatment of osteonecrosis of the femoral head in adults (2019 version)

Osteonecrosis of the femoral head (ONFH) is a common and refractory disease in orthopaedic clinics. The number of patients with ONFH is increasing worldwide every year. There are an estimated 8.12 million patients with nontraumatic osteonecrosis in China alone. Treatment of nontraumatic osteonecrosis has always been a clinical challenge for orthopaedic surgeons. To further standardize diagnosis and treatment of ONFH, these guidelines provide not only basic diagnosis, treatment, and evaluation systems for ONFH but also expert advice and standards in many aspects, including epidemiology, aetiology, diagnostic criteria, pathological staging, prevention and treatment options, and postoperative rehabilitation. The aetiological factors of ONFH can currently be divided into two major categories: traumatic and nontraumatic; however, the specific pathological mechanism of ONFH is not completely clear. Currently, the staging system of ONFH formulated by the Association Research Circulation Osseous is widely used in clinical practice. Based on the changes in the intraosseous blood supply at different stages, the corresponding nonsurgical and surgical treatments are recommended, and when there are risk factors for possible ONFH, certain preventive measures to avoid the occurrence of osteonecrosis are recommended. These guidelines provide brief classification criteria and treatment regimen for osteonecrosis. Specification of the aetiology, treatment plan based on comprehensive consideration of the different stages of osteonecrosis, hip function, age, and occupation of the patients are important steps in diagnosis and developing treatment strategies.

TRANSLATIONAL POTENTIAL OF THIS ARTICLE

New advances in the epidemiology, etiology, pathophysiology, imaging, diagnosis and treatment of ONFH have been renewed in this revision. This guideline can be used for reference by orthopedic professionals and researchers, and for standardized diagnosis and treatment management under the clinical guidance, which is conducive to the prevention, treatment and further research of ONFH, improving the diagnosis and treatment level, making patients' symptoms under good control, and improving their quality of life.

Silencing MicroRNA-137-3p, which Targets RUNX2 and CXCL12 Prevents Steroid-induced Osteonecrosis of the Femoral Head by Facilitating Osteogenesis and Angiogenesis

The main pathogenesis of steroid-induced osteonecrosis of the femoral head (SONFH) includes decreased osteogenic capacity of bone marrow-derived mesenchymal stem cells (BMSCs) and damaged blood supply to the femoral head. MicroRNAs (miRNAs) have been shown to play prominent roles in SONFH development. However, there is no report that a specific miRNA targeting two genes in two different pathogenic pathways has been applied to this disease. The present study investigated the effects of transplantation of miR-137-3p-silenced BMSCs on the prevention and early treatment of SONFH. First, western blotting and dual luciferase assays were employed to verify that miR-137-3p directly targets Runx2 and CXCL12. Then, silencing of miR-137-3p was found to facilitate osteogenic differentiation of BMSCs, which was confirmed by alkaline phosphatase (ALP) staining, alizarin red staining and qRT-PCR. Silencing of miR-137-3p also promoted angiogenesis by human umbilical vein endothelial cells (HUVECs) in the presence or absence of glucocorticoids. Thereafter, overexpression of Runx2 and CXCL12 without the 3′ untranslated region (3′UTR) partially rescued the effects of miR-137-3p on osteogenesis and angiogenesis, respectively. This finding further supported the hypothesis that miR-137-3p exerts its functions partly by regulating the genes, Runx2 and CXCL12. We also demonstrated that SONFH was partially prevented by transplantation of miR-137-3p-silenced BMSCs into a rat model. Micro-CT and histology showed that the transplantation of miR-137-3p-silenced BMSCs significantly improved bone regeneration. Additionally, the results of enzyme-linked immunosorbent assays (ELISA) and flow cytometry suggested that stromal cell-derived factor-1α (SDF-1α) and endothelial progenitor cells (EPCs) participated in the process of vascular repair. Taken together, these findings show that silencing of miR-137-3p directly targets the genes, Runx2 and CXCL12, which can play critical roles in SONFH repair by facilitating osteogenic differentiation and mobilizing EPCs.

Application of biomaterials for the repair and treatment of osteonecrosis of the femoral head

Osteonecrosis of the femoral head (ONFH) is one of the most common causes of hip disability in young adults. However, its cause and pathogenesis remain unclear, and might be caused by a variety of factors. ONFH mainly occurs in young adults. If not treated, 70-80% of patients would progress into femoral head collapse in 3 years, and eventually require hip arthroplasty. Since these patients are younger and more physically active, multiple revision hip arthroplasty might be needed in their life. Repeated revision hip arthroplasty is difficult and risky, and has many complications, which inevitably affects the physical and mental health of patients. To delay the time of total hip arthroplasty for young adult patients with ONFH, biomaterials are used for its repair, which has a high clinical and social value for the retention of the patient's own hip function. At present, there are many types of biomaterials used in repairing the femoral head, there is no uniform standard of use and the clinical effects are different. In this review, the main biomaterials used in the repair of ONFH are summarized and analyzed, and the prospects are also described.

Femoral osteotomies for the treatment of avascular necrosis of the femoral head

OBJECTIVE

Unloading of the area of necrosis out of the weight-bearing region by shifting healthy bone in the main weight-bearing area, which may delay the progression of the necrosis and enable healing.

INDICATIONS

Circumscribed osteonecrosis of the femoral head without advanced degenerative signs (Tönnis grade ≤ 1) in the relatively young patient (age < 50 years).

CONTRAINDICATIONS

Radiographic joint degeneration (> Tönnis grade 1); extensive avascular necrosis (Kerboul angle > 240°); advanced lesions (≥ Association Research Circulation Osseous [ARCO] classification 3b).

SURGICAL TECHNIQUE

By performing a surgical hip dislocation, full access to the hip joint is gained. A femoral varus osteotomy is used to turn the necrotic lesion of the femoral head out of the central weight-bearing area and more medially. Osteosynthesis is performed with an angular stable screw or a blade plate. Via a trapdoor procedure, direct debridement and autologous bone grafting from the trochanter major is possible. The cartilage flap is preserved whenever possible or supplanted by an autologous matrix-induced chondrogenesis (AMIC).

POSTOPERATIVE MANAGEMENT

A passive motion device is installed during hospital stay beginning immediately after surgery to prevent capsular adhesions. After surgery, patients are mobilized with partial weight-bearing of 15 kg with the use of crutches for at least 8 weeks. Forced abduction and adduction as well as flexion of more than 90° are restricted to protect the trochanteric osteotomy. After radiographic confirmation of healing at the 8‑week follow-up, stepwise return to full weight-bearing is allowed and abductor training is initiated.

RESULTS

Nine patients (10 hips) with osteonecrosis of the femoral head were treated with surgical hip dislocation and varus osteotomy. Six hips were treated with autologous bone grafting, four hips with antegrade drilling. Chondral lesions were sutured in four cases, whereas two cases needed an AMIC treatment. The mean age at operation was 29 ± 9 years (20-49), and the mean follow-up time for all patients was 3 ± 2 years (1-7). Conversion to a total hip prosthesis was required for one hip with progressing arthrosis. The other nine hips showed no progression of necrosis and an improved clinical outcome. Complications were pseudarthrosis of the femoral osteotomy and pseudarthrosis of the greater trochanter.

A novel composite scaffold of Cu-doped nano calcium-deficient hydroxyapatite/multi-(amino acid) copolymer for bone tissue regeneration

Background and methods: A Cu-doped composite scaffold of nano calcium-deficient hydroxyapatite (n-CDHA)/multi(amino acid) copolymer (MAC) was prepared. The structure, porosity, morphology and compressive strength of the scaffolds were characterized, the in vitro degradability in phosphate-buffered solution (PBS) and cell responses to the scaffolds were investigated, and in vivo stimulation of bone formation were analyzed.

Results: The scaffolds showed the compressive strength of approximately 12 MPa and total porosity of about 81%. Weight loss of the composite scaffolds was 63% after 16-week immersion in PBS. Cu release in scaffolds showed a marked dependence on the initial amount in the scaffolds over time. Cu-doped n-CDHA/MAC scaffolds with the content of Cu 0.5% and 1% in mass ratio showed better cell responses to proliferation and differentiation of rat bone marrow stromal cells (rBMSCs) than that with no Cu. After 12-week implantation in rabbits, 1% Cu-doped n-CDHA/MAC showed better ability of angiogenesis and osteogenesis compared to 0% Cu-doped n-CDHA/MAC.

Conclusion: The 1% Cu-doped n-CDHA/MAC composite scaffold showed good capacity of angiogenesis and osteogenesis, and the Cu showed positive effects on cell growth and osteogenesis. And it has potential to be used as bone regeneration scaffolds.

What Is the Impact of a Previous Femoral Osteotomy on THA? A Systematic Review

BACKGROUND

Femoral osteotomies have been widely used to treat a wide range of developmental and degenerative hip diseases. For this purpose, different types of proximal femur osteotomies were developed: at the neck as well as at the trochanteric, intertrochanteric, or subtrochanteric levels. Few studies have evaluated the impact of a previous femoral osteotomy on a THA; thus, whether and how a previous femoral osteotomy affects the outcome of THA remains controversial.

QUESTIONS/PURPOSES

In this systematic review, we asked: (1) What are the most common complications after THA in patients who have undergone femoral osteotomy, and how frequently do those complications occur? (2) What is the survival of THA after previous femoral osteotomy? (3) Is the timing of hardware removal associated with THA complications and survivorship?

METHODS

A systematic review was carried out on PubMed, the Cochrane Systematic Reviews Database, Scopus, and Embase databases with the following keywords: "THA", "total hip arthroplasty", and "total hip replacement" combined with at least one of "femoral osteotomy" or "intertrochanteric osteotomy" to achieve the maximum sensitivity of the search strategy. Identified studies were included if they met the following criteria: (1) reported data on THAs performed after femoral osteotomy; (2) recorded THA followup; (3) patients who underwent THA after femoral osteotomy constituted either the experimental group or a control group; (4) described the surgical and clinical complications and survivorship of the THA. The database search retrieved 383 studies, on which we performed a primary evaluation. After removing duplicates and completing a full-text evaluation for the inclusion criteria, 15 studies (seven historically controlled, eight case series) were included in the final review. Specific information was retrieved from each study included in the final analysis. The quality of each study was evaluated with the Methodological Index for Non-randomized Studies (MINORS) questionnaire. The mean MINORS score for the historically controlled studies was 14 of 24 (range, 10-17), whereas for the case series, it was 8.1 of 16 (range, 5-10).

RESULTS

The proportion of patients who experienced intraoperative complications during THA ranged from 0% to 17%. The most common intraoperative complication was femoral fracture; other intraoperative complications were difficulties in hardware removal and nerve palsy; 15 studies reported on complications. The survivorship of THA after femoral osteotomy in the 13 studies that answered this question ranged from 43.7% to 100% in studies that had a range of followup from 2 to 20 years. The timing of hardware removal was described in five studies, three of which detailed more complications with hardware removal at the time of THA.

CONCLUSIONS

This systematic review demonstrated that THA after femoral osteotomy is technically more demanding and may carry a higher risk of complications than one might expect after straightforward THA. Staged hardware removal may reduce the higher risk of intraoperative fracture and infection, but there is no clear evidence in support of this contention. Although survivorship of THA after femoral osteotomy was generally high, the studies that evaluated it were generally retrospective case series, with substantial biases, including selection bias and transfer bias (loss to followup), and so it is possible that survivorship of THA in the setting of prior femoral osteotomy may be lower than reported.

LEVEL OF EVIDENCE

Level III, therapeutic study.

A mathematical model for predicting postoperative leg shortening after curved intertrochanteric varus osteotomy for osteonecrosis of the femoral head

Despite good clinical outcomes associated with curved intertrochanteric varus osteotomy for the treatment of osteonecrosis of the femoral head, post-operative leg-length discrepancy is frequently reported and might reduce patient satisfaction. Although previous report showed that varus angulation affected post-operative leg-length discrepancy, sufficient varus angulation is the most important factor for obtaining a lateral intact portion. Therefore, to ensure better postoperative outcomes, detection of other parameters associated with leg shortening may prove useful. This study aimed to detect other factors influencing post-operative leg-length discrepancy and to develop a theory for pre-operative planning. The study included 42 hips of 36 patients with osteonecrosis of the femoral head [25 men and 11 women; mean age at the time of surgery, 33.8 years (range, 17 to 53 years)]. Patients were assessed their clinical and radiological results bofore and after surgery. Additionally, a mathematical model was developed to predict leg shortening after curved intertrochanteric varus osteotomy based on the degree of varus angulation and the distance between the femoral head and osteotomy arc centers. Predicted and actual leg shortening in patients were compared to verify the accuracy of our model. Post-operatively, mean varus angle was 21.7° (range, 15 to 38°) and mean leg shortening was 1.7 mm (range, -5.1 to 11.4 mm). Univariate analysis showed that varus angulation and lateral shift of the osteotomy arc might influence the degree of leg shortening. Furthermore, mathematically predicted leg shortening significantly correlated with actual leg shortening (r = 0.905, p < 0.001), suggesting the usefulness of our model for predicting complications of curved intertrochanteric varus osteotomy. This study indicates the importance of not positioning the center of the osteotomy arc lateral from the center of the femoral head to minimize leg shortening after curved intertrochanteric osteotomy.

[Strategy and discussion of hip joint preserving surgery treatments for adult osteonecrosis of the femoral head]

As a common disease in orthopedics, osteonecrosis of the femoral head (ONFH) frequently occurs among young and middle-aged people. Hip joint preserving surgery has attracted more and more attention due to the fact that artificial joint prosthesis has a certain useful life and the rate of hip joint revision is high and the higher risk of many complications. There are a large number of operative methods for preserving hip joint in clinical practice without definitive effectiveness. How to choose appropriate surgical methods at the right time is also a continuous understanding. The pathological process of necrosis of the femur helps to choose the choice of the femoral head necrosis for the treatment of hip operation. Core decompression and impaction bone grafting with simple operative methods can relieve internal pressure of femoral head and pain symptoms, but they cannot remove necrotic bone completely. Hence, they are only used for ONFH in the early stage. Vascularized bone transplantation can fill defects of the former, as it can not only completely remove necrotic bone, but also provide bone graft with nourishing vessels for femoral head, being beneficial to reconstruct the bone structure of femoral head. Subsequently, the application of tantalum rod can provide mechanical support for femoral head to prevent the collapse of femoral head. Hip joint preserving surgery, in recent years, has been performed increasingly, and has obtained improvement in clinical effects. The multiple combination of a variety of its operative methods provides more effective treatments for ONFH. It is an essential notion that hip joint preserving surgery, however with any operative method, should as far as possible select a surgical plan with little trauma, simple methods, and little injury of hip joint bone structure based on ensuring the effectiveness.

Chinese Guideline for the Diagnosis and Treatment of Osteonecrosis of the Femoral Head in Adults

The treatment of adult osteonecrosis of the femoral head (ONFH), with 8.12 million patients in China, remains a challenge to surgeons. To standardize and improve the efficacy of the treatment of ONFH, Chinese specialists updated the experts' suggestions in March 2015, and an experts' consensus was given to provide a current basis for the diagnosis, treatment and evaluation of ONFH. The current guideline provides recommendations for ONFH with respect to epidemiology, etiology, diagnostic criteria, differential diagnosis, staging, treatment, as well as rehabilitation. Risk factors of non-traumatic ONFH include corticosteroid use, alcohol abuse, dysbarism, sickle cell disease and autoimmune disease and others, but the etiology remains unclear. The Association Research Circulation Osseous (ARCO) staging system, including plain radiograph, magnetic resonance imaging, radionuclide examination, and histological findings, is frequently used in staging ONFH. A staging and classification system was proposed by Chinese scholars in recent years. The major differential diagnoses include mid-late term osteoarthritis, transient osteoporosis, and subchondral insufficiency fracture. Management alternatives for ONFH consist of non-operative treatment and operative treatment. Core decompression is currently the most common procedure used in the early stages of ONFH. Vascularized bone grafting is the recommended treatment for ARCO early stage III ONFH. This guideline gives a brief account of principles for selection of treatment for ONFH, and stage, classification, volume of necrosis, joint function, age of the patient, patient occupation, and other factors should be taken into consideration.

An evidence-based guide to the treatment of osteonecrosis of the femoral head

Non-traumatic osteonecrosis of the femoral head is a potentially devastating condition, the prevalence of which is increasing. Many joint-preserving forms of treatment, both medical and surgical, have been developed in an attempt to slow or reverse its progression, as it usually affects young patients. However, it is important to evaluate the best evidence that is available for the many forms of treatment considering the variation in the demographics of the patients, the methodology and the outcomes in the studies that have been published, so that it can be used effectively. The purpose of this review, therefore, was to provide an up-to-date, evidence-based guide to the management, both non-operative and operative, of non-traumatic osteonecrosis of the femoral head. Cite this article: Bone Joint J 2017;99-B:1267-79.

Analysis of damage in relation to different classifications of pre-collapse osteonecrosis of the femoral head

Objective This study aimed to investigate the damage pattern of the stress transfer path (STP) for the Japanese Investigation Committee (JIC) classification of pre-collapse osteonecrosis of the femoral head. We aimed to provide a specific biomechanical basis for treatment decisions of each subtype. Methods Five computational models were used in the experiment. Different necrotic classifications were simulated based on the JIC classification system. Damage patterns of the STP were used for qualitative assessment and average stresses were used for quantitative analysis. Results The STP of type A showed a strong similarity to the healthy level, which was consistent with the bone density distribution in X-rays and previous simulations results. The damaged area of principal stress of type B was approximately 25% of the healthy level. The STPs of types C1 and C2 were broken and the damaged areas of principal stress were more than 50% of the healthy level. The efficiency of stress transfer was reduced. Conclusions These results indicate that the damage patterns and stress transfer efficiency of the femoral head are associated with necrotic classifications.

Long-term results of rotational acetabular osteotomy for osteonecrosis with collapse of the femoral head in young patients

PURPOSE

The surgical treatment of osteonecrosis with collapse of the femoral head is still controversial. The purpose of this study was to investigate the clinical outcome of rotational acetabular osteotomy by Ninomiya and Tagawa for osteonecrosis of the femoral head in young patients.

PATIENTS AND METHODS

Rotational acetabular osteotomy was performed in 202 consecutive patients between 1995 and 2003. Among them, rotational acetabular osteotomy with osteonecrosis of the femoral head was performed in 31 patients (42 hips). The mean age at the time of surgery was 31.2 years (range 16-45). The mean duration of follow-up was 16.1 years (range 13.1-21 years).

RESULTS

The mean preoperative Japanese Orthopedic Association hip score of 56.8 points improved to a mean of 72.4 points at the final follow-up. The 10-year survival rate with conversion to total hip arthroplasty as an end-point was 91.9%, and the 15-year survival rate was 75.5%, the 20-year survival rate was 67.9%. The conversion to total hip arthroplasty was performed in nine hips. The average time to the conversion to total hip arthroplasty was 12.1 years.

CONCLUSIONS

Even though the necrotized range is wide, if normal cartilage remains on the lateral side of the femoral head, it can be utilized for the weight-bearing region by laterally rotating the acetabulum. Since the outcome was favorable, we believe that this is a valuable treatment option for this disease.

Guideline for Diagnostic and Treatment of Osteonecrosis of the Femoral Head

There is a new knowledge for clinical presentations and findings of imagine in patients with osteonecrosis of the femoral head (ONFH) in recent more than ten years. According to clinical data in Chinese huge patients with ONFH, the guideline for diagnosis and treatment of ONFH has been put forward by Chinese specialists. The newer contents of guideline include the definition for predisposing risk factors of ONFH, the new knowledge for clinical manifestations, the new interpretation for changes of imagine, important differential diagnosis. Based on the supplementary and revision for widely used staging and classification system, the new Chinese staging and classification system have been established. The advantages of Chinese staging and classification system accord with clinical and pathological features, it could be predicted the prognosis, and clinical applications are convenient. The guideline gives a brief account of principles for treatment selection and treatment methods for enhancement of diagnosis and treatment for ONFH.

Nontraumatic Osteonecrosis of the Femoral Head: Where Do We Stand Today? A Ten-Year Update

➤ Although multiple theories have been proposed, no one pathophysiologic mechanism has been identified as the etiology for the development of osteonecrosis of the femoral head. However, the basic mechanism involves impaired circulation to a specific area that ultimately becomes necrotic.➤ A variety of nonoperative treatment regimens have been evaluated for the treatment of precollapse disease, with varying success. Prospective, multicenter, randomized trials are needed to evaluate the efficacy of these regimens in altering the natural history of the disease.➤ Joint-preserving procedures are indicated in the treatment of precollapse disease, with several studies showing successful outcomes at mid-term and long-term follow-up.➤ Studies of total joint arthroplasty, once femoral head collapse is present, have described excellent outcomes at greater than ten years of follow-up, which is a major advance and has led to a paradigm shift in treating these patients.➤ The results of hemiresurfacing and total resurfacing arthroplasty have been suboptimal, and these procedures have restricted indications in patients with osteonecrosis of the femoral head.

Conservative surgery for the treatment of osteonecrosis of the femoral head: current options

The prevention of femoral head collapse and the maintenance of hip function would represent a substantial achievement in the treatment of osteonecrosis of the femoral head; however it is difficult to identify appropriate treatment protocols to manage patients with pre-collapse avascular necrosis in order to obtain a successful outcome in joint preserving procedures. Conservative treatments, including pharmacological management and biophysical modalities, are not supported by any evidence and require further investigation. The appropriate therapeutic approach has not been identified. The choice of surgical procedures is based on patient clinical conditions and anatomopathological features; preservation of the femoral head by core decompression may be attempted in younger patients without head collapse. Biological factors, such as bone morphogenetic proteins and bone marrow stem cells, would improve the outcome of core decompression. Another surgical procedure proposed for the treatment of avascular necrosis consists of large vascularized cortical bone grafts, but its use is not yet common due to surgical technical issues. Use of other surgical technique, such as osteotomies, is controversial, since arthroplasty is considered as the first option in case of severe femoral head collapse without previous intervention.

Management of femoral head osteonecrosis: Current concepts

Osteonecrosis of femoral head (ONFH) is a disabling condition of young individuals with ill-defined etiology and pathogenesis. Remains untreated, about 70-80% of the patients progress to secondary hip arthritis. Both operative and nonoperative treatments have been described with variable success rate. Early diagnosis and treatment is the key for success in preserving the hip joint. Once femoral head collapses (>2 mm) or if there is secondary degeneration, hip conservation procedures become ineffective and arthroplasty remains the only better option. We reviewed 157 studies that evaluate different treatment modalities of ONFH and then a final consensus on treatment was made.

Relationship between preservation of the lateral pillar and collapse of the femoral head in patients with osteonecrosis

It is difficult to predict if and when the femoral head will collapse and whether the collapse can be minimized. This study examined the final outcome of early-stage osteonecrosis of the femoral head (ONFH) using magnetic resonance imaging to verify the relationship between preservation of the lateral pillar and collapse of the femoral head. A midcoronal section of the femoral head was divided into 3 pillars (medial, central, and lateral) on a T1-weighted image. According to the site of necrosis on the lateral pillar, the necrosis was divided into 3 types: I, the necrosis occupies the central and medial pillars, and the lateral pillar is preserved; II, the necrosis partially occupies the lateral pillar; and III, the necrosis totally occupies the lateral pillar. One group of 87 patients (127 hips) with Association for Research on Osseous Circulation (ARCO) stage I ONFH underwent nonoperative treatment and were followed for 3 to 8 years (average, 6.2 years). Another group of 42 patients (72 hips) with ARCO stage I ONFH underwent debridement and impacted bone graft and were followed for 5 to 9 years (average, 7.1 years). In both groups, the more preserved the lateral pillar, the less collapse occurred. The authors concluded that whether ONFH progressed to collapse is determined by preservation of the lateral pillar. The lateral pillar is the keystone for maintaining the sphere of the femoral head and its preservation.

The effect of postoperative corticosteroid administration on free vascularized fibular grafting for treating osteonecrosis of the femoral head

Free vascularized fibular grafting (FVFG) has been reported to be an effective method of treating osteonecrosis of the femoral head (ONFH). This study evaluated whether postoperative maintenance doses of corticosteroids had an adverse effect on FVFG outcomes in patients with corticosteroid-induced ONFH. We retrospectively reviewed the records of 39 patients (67 hips) who had received maintenance doses of corticosteroids following FVFG. This group was matched to a group of patients who had not received corticosteroids treatment after operation. The mean follow-up duration was 5.4 years for the postoperative corticosteroid administration group (PCA group) and 5.0 years for the control group. At the latest follow-up, the average increase in Harris hip score was 11.1 ± 8.7 points for all hips in the PCA group and 12.6 ± 7.4 points for all hips in the control group (P > 0.05). In the PCA group, through radiographic evaluation, 49 hips were improved, 10 hips appeared unchanged, and 8 hips appeared worse. In the control group, 47 hips were improved, 13 hips appeared unchanged, and 7 hips appeared worse. The results suggested that postoperative maintenance doses of corticosteroids do not have an adverse effect on FVFG outcomes in patients with corticosteroid-induced ONFH.

Osteonecrosis of the hip: treatment options and outcomes

This article reviews the literature regarding the outcomes of various nonoperative and operative treatment options for osteonecrosis of the hip. This article provides the orthopedic community with the latest evidence regarding the suitability of currently available treatment modalities in various stages of the disease.

Lesser trochanteric osteotomy in total hip arthroplasty for treating CROWE type IV developmental dysplasia of hip

PURPOSE

The study was designed to evaluate the efficacy and safety of lesser trochanteric osteotomy for femoral shortening in total hip arthroplasty in treatment of 28 cases of CROWE IV developmental dysplasia of the hip (DDH).

METHODS

Patients underwent progressive femoral shortening at the level of lesser trochanteric to make reduction possible into the anatomical acetabulum in all hips. The results were collected and evaluated clinically and radiographically.

RESULTS

The mean follow-up period was 55.3 months. The average postoperative leg length discrepancy was eight millimetres for unilateral THA patients. A modified Merle d'Aubigné scale was improved from 9.3 preoperatively to 15.9 postoperatively. Sciatic nerve palsy was confirmed in two hips which resolved completely in six months. The Trendelenburg sign was positive in two hips at the final follow-up. No revision surgery was required by the final follow-up.

CONCLUSION

Lesser trochanteric osteotomy proved to be safe and effective in femoral shortening for treatment of CROWE IV DDH without the problem of nonunion at the site of osteotomy.

Evaluation of bipolar hemiarthroplasty for the treatment of steroid-induced osteonecrosis of the femoral head

PURPOSE

Bipolar hemiarthroplasty (BHA) for idiopathic osteonecrosis of the femoral head (ONFH) is performed at our institution. The purpose of this study was to evaluate the clinical and radiographic findings after BHA for the treatment of steroid -induced ONFH.

METHODS

Thirty-seven hips in 27 patients were assessed (seven men, 11 hips; 20 women, 26 hips), average patient age at the time of surgery of 42.6 (range 20-83) years, with steroid-induced ONFH treated with BHA between 1995 and 2005. The mean follow-up duration was approximately ten (range five to 15) years. Patients were evaluated according to the Japan Orthopaedic Association (JOA) hip score. Kaplan-Meier survivorship was calculated to examine revision arthroplasty failure rate. Radiographic analysis of loosening included radiolucent lines and osteolysis of the acetabulum or femur. Causes of loosening were analysed using multiple logistic regression.

RESULT

JOA hip score increased from 53 points (preoperative) to 87 points (final follow-up). Survival rates were 96.8 % and 78.6 % at ten and 15 years, respectively. Prosthesis loosening occurred on the acetabular side in five hips (13.5 %). No femoral-component loosening was observed. BHA had poor results in patients with Association Research Circulation Osseous (ARCO) stage IV ONFH and in patients under 40 years of age.

CONCLUSION

BHA, with strict surgical indications, may be a good option for treating ONFH. Based on these results, total hip arthroplasty is recommended for patients with ARCO stage IV ONFH or for patients under 40 years of age.